blackmagic/src/platforms/stm32/traceswodecode.c

70 lines
2.3 KiB
C

/*
* This file is part of the Black Magic Debug project.
*
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* Print decoded swo stream on the usb serial */
#include "general.h"
#include "cdcacm.h"
#include "traceswo.h"
/* SWO decoding */
/* data is static in case swo packet is astride two buffers */
static uint8_t swo_buf[CDCACM_PACKET_SIZE];
static int swo_buf_len = 0;
static uint32_t swo_decode = 0; /* bitmask of channels to print */
static int swo_pkt_len = 0; /* decoder state */
static bool swo_print = false;
/* print decoded swo packet on usb serial */
uint16_t traceswo_decode(usbd_device *usbd_dev, uint8_t addr,
const void *buf, uint16_t len) {
if (usbd_dev == NULL) return 0;
for (int i = 0; i<len; i++) {
uint8_t ch=((uint8_t*)buf)[i];
if (swo_pkt_len == 0) { /* header */
uint32_t channel = (uint32_t)ch >> 3; /* channel number */
uint32_t size = ch & 0x7; /* drop channel number */
if (size == 0x01) swo_pkt_len = 1; /* SWO packet 0x01XX */
else if (size == 0x02) swo_pkt_len = 2; /* SWO packet 0x02XXXX */
else if (size == 0x03) swo_pkt_len = 4; /* SWO packet 0x03XXXXXXXX */
swo_print = (swo_pkt_len != 0) && ((swo_decode & (1UL << channel)) != 0UL);
} else if (swo_pkt_len <= 4) { /* data */
if (swo_print) {
swo_buf[swo_buf_len++]=ch;
if (swo_buf_len == sizeof(swo_buf)) {
if (cdcacm_get_config() && gdb_uart_get_dtr()) /* silently drop if usb not ready */
usbd_ep_write_packet(usbd_dev, addr, swo_buf, swo_buf_len);
swo_buf_len=0;
}
}
--swo_pkt_len;
} else { /* recover */
swo_buf_len=0;
swo_pkt_len=0;
}
}
return len;
}
/* set bitmask of swo channels to be decoded */
void traceswo_setmask(uint32_t mask) {
swo_decode = mask;
}
/* not truncated */